1. Field of the Invention:
The invention relates to devices for enchancing the quality and realism of electronically reproduced sound. In particular, it relates to a device which allows sound from both earphones and speakers powered by the same source to be heard simultaneously.
2. Description of the Prior Art:
Various electronic sound delay/sound attenuation systems have been used to increase the sense of realism when playing back music via loudspeakers. These systems take musical signals from a primary amplifier and feed them to a computer or other type of processor which in turn feeds the signals to a secondary amplifier and secondary set of speakers. While the primary amplifier drives speakers placed in front of the listeners, the electronic delay system feeds information to the secondary amplifier which drives speakers placed behind the listeners. The more sophisticated systems delay and attenuate frequency separately and randomly for each channel. Users can alter the delay time to simulate ambience that would be present in rooms of varying size.
These electronic sound delay systems are expensive, some of them display limited results, and to date have not become a popular part of the average listeners' stereo system. However, similar and perhaps superior increases in ambience or presence (that is, the sense of being at a "live" concert) can be created, by use of the present invention, without specialized electronic delay systems. By using the standard listener distance of six to eight feet or more for stereo sound away from loudspeakers and by simultaneously listening to earphones that are held just off the ears by the invention and that are connected to the same amplifier that is driving the loudspeakers, a dramatic increase in depth and ambience of sound will be experienced.
The prior art includes structures for holding earphones at a distance from the ear, but they differ substantially from the invention disclosed herein. Lahti U.S. Pat. No. 3,488,457, describes a device which allows the user to change the relative lateral displacement of the sound energy emitting aperture as it relates to the ear canal. However, this device is not designed to allow sound from an outside source to reach the ear unimpeded, and this device is not designed to allow a change in the earphone speaker's distance from the ear.
Jacobson U.S. Pat. No. 4,302,635, discloses an earphone with a pair of cushions that snap onto the sound transducer element, but these cushions are designed as a part of the earphone and relate to comfort rather than acoustic distance from the ear. This system is not designed to let sound from an outside source reach the ear.
Telford U.S. Pat. No. 4,529,057, discloses an ear protector or defender which does allow some sound from sources outside the earphone via a port that can be opened or closed. However, the device is not designed to allow the user to hear outside sound freely, unimpeded, and from front and back, up and down directions simultaneously.
Scalzo et al. U.S. Pat. No. 4,523,661, reveals a sound attenuating earcup assembly that holds the earphone's speakers away from the ear, but the stated purpose is to isolate the ear of a wearer from ambient sound while allowing the user to hear enough for external communication. The earcup assembly is not designed to provide free access of external sound waves from as many directions as possible.
Fidi et al. U.S. Pat. No. 4,572,324, discloses an earphone with a sound impermeable cushion that rests on the head plus a sound permeable section that spaces the earphone's speaker away from the ear. According to the patent, the type of sound permeable section suggested allows an earphone speaker to deliver a full frequency range of 20 Hz to 2 Khz to the ear because it sets up a defined acoustic impedance. The other object of the specified sound permeable layer is to increase comfort by allowing ventilation. Unlike the invention proposed herein, there is no mention of the permeable layer being designed specifically to allow maximum sound to the ear from sources outside the earphone, and there is no mention of using the earphone spacers to hold the earphone's speaker within a critical distance from the ear in respect to outside sound sources Finally, these earphone cushions are designed to be a part of the earphone unit rather than be separate from and used with any earphone, unlike the preferred embodiment of the invention proposed herein.